1. Field of the Invention
The present invention relates to an evaporative fuel processing device for collecting evaporative fuel, generated within a fuel tank in a vehicle, by means of a canister to prevent the evaporative fuel from being released into the atmosphere.
2. Description of the Prior Art
The amount of evaporative fuel generated in a fuel tank in a vehicle during refueling is larger than that of evaporative fuel generated during normal operation (i.e., during parking and traveling of the vehicle). Therefore, it is necessary to reliably introduce the evaporative fuel generated during refueling into a canister, thereby preventing it from being released into the atmosphere. An evaporative fuel processing device is conventionally known which is intended to collect evaporative fuel generated during refueling in this manner, and which is described in Japanese Utility Model Publication No. 37006/93.
The above prior art evaporative fuel processing device includes an on-off valve provided in an intermediate portion of a charge passage, which connects an upper space in the fuel tank and the canister, so that the on-off valve is opened upon insertion of a refueling nozzle into a refueling line (pipe) during refueling of the fuel tank, thereby permitting the evaporative fuel generated during refueling to be guided into the canister. In order to prevent the fuel from flowing through the charge passage into the canister, a float valve is also mounted at a lower end of the charge passage which opens into the fuel tank.
However, a problem with the above prior art evaporative fuel processing device is that the number of parts is increased which increases the cost due to the need for both a) the on-off valve opened by the insertion of the refueling nozzle and b) the float valve closed by rising of the liquid level in the fuel tank.